A croissant and latte on the way to work may not always be a healthier option than stopping at a "greasy spoon" cafe, according to a campaign group that aims to reduce salt in diets.

Many foods eaten for breakfast contain high levels of salt. While many consumers recognise there are high salt levels in traditional English fry-ups including bacon, beans and sausages, far fewer realise that sweet pastries on offer at high street coffee chains could also contribute significantly to busting the 6g of salt daily target set for adults by the government's Food Standards Agency (FSA).

A Starbucks' cinnamon swirl, for instance, contained more than twice the amount of salt contained in a rasher of bacon from a supermarket, while American-style muffins contained the same amount of salt or more than a standard pack of ready salted crisps. One Costa muffin had three times as much as a packet of crisps, a survey by Consensus Action on Salt and Health (Cash) revealed.

Eating too much salt increases the risk of high blood pressure, and therefore a stroke or heart attack. About three-quarters of the salt we eat is already in the food we buy, the rest is added during cooking and at the table. The FSA says the average daily adult salt intake is 8.6g, down from 9.5g in 2001. It wants to make FSA targets for different types of food tougher, but these only apply to foods bought from shops. Although the FSA is turning its attention to caterers and coffee shops, Cash believes many people who eat breakfast out are unaware of how salty it can be.

Cash, which has worked closely with the FSA, surveyed more than 200 breakfast items over the past four months, including those at seven leading high street chains. It gleaned information from product labels, company websites and customer service departments and by phoning cafes. These checks found that the salt content even of muffins could vary widely.

Although full English fry-ups may contain enough salt for a whole day's "allowance", there were cooked breakfasts that could remain on the menu, said Cash. One poached egg, one tomato, mushrooms and a slice of toast and butter could contain as little as 0.7g of salt. Even two sausages, a fried egg, one tomato and a slice of toast and butter, might, at 2.3g, be little more salty than a coffee shop latte and pastry.

Costa said it was working with the FSA to develop standards that met future guidelines. Its website gave nutritional analysis of all products. Starbucks said it was continually reviewing its range and also gave nutritional information on its website.

• This article was amended on Wednesday November 5 2008. We were wrong to report that the Food Standards Agency says that the average daily adult salt intake is 8.6g, down from 9.5g in 1990. The FSA says that salt intakes were at 9.5g in 2001. This has been changed.